Hydroxyalkyl cellulose is a kind of cellulose ether obtained by reacting cellulose and an alkylene oxide-based etherifying agent, and is an environmentally-friendly water-soluble polymer having excellent water solubility and thickening power and thus extensively used for paints, daily supplies, construction, emulsion polymerization, and the like.
Hydroxyalkyl cellulose, as illustrated in FIG. 1, is generally formed by adding cellulose, which is a main raw material, in a reaction solvent, adding an alkaline aid to perform alkalization for a predetermined time and thus form alkaline cellulose, adding an etherifying agent (for example, alkylene-based etherifying agent (ethylene oxide)), and increasing a temperature to 100° C. to perform a reaction, and subsequently, cooling is performed to 60° C. and an oxidizing agent is then added to perform neutralization. Thereafter, a post-process such as separation, filtering, drying, and pulverization processes is performed to manufacture hydroxyalkyl cellulose in a powder phase.
Physical properties of hydroxyalkyl cellulose manufactured as described above are represented by a viscosity of a solution thereof, and the viscosity can be adjusted through the degree of polymerization of cellulose that is mostly used as a raw material. However, ultra-low viscosity hydroxyalkyl cellulose applied for polymerization and dielectric purposes cannot be directly manufactured by the aforementioned method.
For that reason, in order to manufacture ultra-low viscosity hydroxyalkyl cellulose, a method of manufacturing ultra-low viscosity hydroxyalkyl cellulose through acid treatment of chlorine, hydrogen peroxide, and the like on a final product that is subjected to synthesis, washing, and pulverization processes is extensively used.
However, the method of manufacturing ultra-low viscosity hydroxyalkyl cellulose through acid treatment of the final product requires investment of additional equipment and a sufficient space for the additional equipment, and has a drawback in that productivity is reduced due to an additional process.
Therefore, the present inventors have studied a method of manufacturing ultra-low viscosity hydroxyalkyl cellulose in order to solve the aforementioned drawback, and found that ultra-low viscosity hydroxyalkyl cellulose can be manufactured by introducing a partial neutralization method during a process of synthesizing hydroxyalkyl cellulose, that is, introducing hydrogen peroxide after first neutralization to perform a reaction and then performing second neutralization, thereby completing the present invention.